In the manufacture of foods and beverages, hard surfaces commonly become contaminated with carbohydrate, proteinaceous, hardness soils and other soils. Such soils can arise from the manufacture of both liquid and solid foodstuffs. Carbohydrate soils including cellulosics, monosaccharides, disaccharides, oligosaccharides, starches, gums and other complex materials, when dried, can form tough, hard to remove soils particularly when combined with other soil types. Similarly, other materials arising from foodstuffs including proteins, enzymes, fats and oils can also form contaminating, hard to remove soil, residues. One particular problem in the manufacture of beverages such as malt beverages, fruit juices such a citrus products, dairy products and others, can be the removal of largely carbohydrate soils that can also contain other soil components such as proteins, enzymes, fats, oils and others. The removal of such carbohydrate soils can be a significant problem.
Prior art compositions formulated for soil removal include various disclosures relating to acid cleaners containing a formulated detergent composition. Casey, U.S. Pat. No. 4,587,030 discloses a composition formulated to remove soap scum and hardness components using an aqueous base containing a surfactant system, and formulations of an amine oxide and cosolvent. Reihm et al., U.S. Pat. No. 4,699,728 discloses a fiberglass cleaner composition containing an organophosphonic acid/acrylic acid sequestrant in combination with a betaine surfactant. Heinhuis-Walther et al., U.S. Pat. No. 5,000,867 discloses a disinfectant composition comprising quaternary ammonium antimicrobials combined with organic and/or inorganic acids. Oaks et al, U.S. Pat. No. 5,437,868 discloses acidic peroxyacid antimicrobial compositions that can be formulated with functional materials. Gorin et al., U.S. Pat. No. 5,712,241 discloses a light duty liquid detergent containing a specific surfactant system. Ihns et al., U.S. Pat. No. 5,861,366 discloses soil removing agents containing an enzyme in formulations specifically designed to enhance proteolytic soil removal.
In formulating effective cleaning materials, formulators are constrained by available low cost materials, the use of materials that provide useful properties and compatibility and stability of the ingredients used. Combining acidic materials, and other materials such as enzymes can pose stability problems for the active materials. Further. obtaining cleaning and bactericidal effectiveness including a sanitizing effect is difficult for common formulator applications. Many of the formulations in the prior art have stability limitations or do not provide sufficient cleaning and sanitizing to be effective in the clean-in-place food or beverage applications.
Clean-in-place cleaning techniques are a specific cleaning regimen adapted for removing soils from the internal components of tanks, lines, pumps and other process equipment used for processing typically liquid product streams such as beverages, milk, juices, etc. Clean-in-place cleaning involves passing cleaning solutions through the system without dismantling any system components. The minimum clean-in-place technique involves passing the cleaning solution through the equipment and then resuming normal processing. Any product contaminated by cleaner residue can be discarded. Often clean-in-place methods involve a first rinse, the application of the cleaning solutions, a second rinse with potable water followed by resumed operations. The process can also include any other contacting step in which a rinse, acidic or basic functional fluid, solvent or other cleaning component such as hot water, cold water, etc. can be contacted with the equipment at any step during the process. Often the final potable water rinse is skipped in order to prevent contamination of the equipment with bacteria following the cleaning sanitizing step. The formulations of the invention that can be used in the clean-in-place technique typically comprise a mineral acid optionally in combination with an organic acid, a hydrocarbon ether solvent or a hydrocarbon alcohol solvent, a sequestrant composition, an ether amine composition and a variety of surfactant materials.
A substantial need exists for improved soil removal detergents and methods using acidic formulations. Further, a substantial need exists for compositions and methods for removing soil from hard surfaces such as conduits, tanks and pumps used in beverage manufacture using a clean-in-place technique.